I think the split mode is intended for exactly that style of play. Full mode makes it easy for players to just pound out the chords and still get the acc recognition. If you solo on top of a chord in full mode, it can't help but try to "catch up" to all the new chords presented. Doesn't split mode offer you the result you want with no compromise? You can match the tones on each side of the split so it will be the same thing as a full mode, but with the added finesse of split mode recognition.
Seems like it's not a bug at all, but a design feature to facilitate more playing styles. I wouldn't want an arranger to try to follow my solo lines.... just the chord structure.